KR20160029163A - a hydraulic actuator - Google Patents

a hydraulic actuator Download PDF

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Publication number
KR20160029163A
KR20160029163A KR1020140117401A KR20140117401A KR20160029163A KR 20160029163 A KR20160029163 A KR 20160029163A KR 1020140117401 A KR1020140117401 A KR 1020140117401A KR 20140117401 A KR20140117401 A KR 20140117401A KR 20160029163 A KR20160029163 A KR 20160029163A
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KR
South Korea
Prior art keywords
cable
pulley
piston
force
cylinder chamber
Prior art date
Application number
KR1020140117401A
Other languages
Korean (ko)
Inventor
김진현
조정산
박상덕
박병윤
Original Assignee
한국생산기술연구원
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 한국생산기술연구원 filed Critical 한국생산기술연구원
Priority to KR1020140117401A priority Critical patent/KR20160029163A/en
Publication of KR20160029163A publication Critical patent/KR20160029163A/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/082—Characterised by the construction of the motor unit the motor being of the slotted cylinder type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1409—Characterised by the construction of the motor unit of the straight-cylinder type with two or more independently movable working pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1423—Component parts; Constructional details
    • F15B15/1447—Pistons; Piston to piston rod assemblies
    • F15B15/1452—Piston sealings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00—Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/005—With rotary or crank input
    • F15B7/006—Rotary pump input
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H7/00—Gearings for conveying rotary motion by endless flexible members
    • F16H7/04—Gearings for conveying rotary motion by endless flexible members with ropes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J1/00—Pistons; Trunk pistons; Plungers
    • F16J1/10—Connection to driving members
    • F16J1/24—Connection to driving members designed to give the piston some rotary movement about its axis

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Actuator (AREA)

Abstract

The present invention relates to a hydraulic actuator, and more particularly to a hydraulic actuator in which a pair of hydraulic actuators are arranged upward, downward, leftward and rightward in the same direction to produce movement in both directions, and a lightweight, To reduce weight and volume, and to facilitate the design of a mechanism. A cylinder chamber in which a pair of pistons are installed so as to be positioned up and down in the same direction or left and right, ; A cable connected to each of the cylinders through the piston to move in conjunction with the operation of the piston and to easily change the direction of the force; A pulley formed on one side of the cylinder chamber and having one or more cable receiving grooves formed on an outer circumferential surface formed in a disk shape so as to convert a transmission direction of a force or generate a large force with a small force; .

Description

A hydraulic actuator

The present invention relates to a hydraulic actuator, and more particularly to a hydraulic actuator in which a pair of hydraulic actuators are arranged upward, downward, leftward and rightward in the same direction to produce movement in both directions, and a lightweight, To reduce weight and volume, and to facilitate the design of a mechanism.

Generally, robotic technology is applied to improve the workability and safety in the medical field, the automobile industry field, the military industry field, the mechatronics field, etc. In the medical field, for example, a surgical arm and a robot And various types of actuators using electricity, hydraulic pressure, compressed air, etc. are used for this purpose.

However, the conventional hydraulic actuator is constituted of a cylinder chamber, a piston and a rod in the form of a rod, and the pressure of the hydraulic fluid flowing into the cylinder chamber prevents the rod, which operates linearly by the force generated in proportion to the piston cross- The weight and volume of the hydraulic actuator are increased due to the manufacture of steel having a large diameter for the reason that the driving speed of the hydraulic actuator for driving the robot or the machine is lowered and the miniaturization can not be achieved.

Further, since a conventional hydraulic actuator uses a quadric link mechanism or the like for power transmission, many mechanical parts are used, the weight becomes heavy, and the number of parts where the clearance is generated is increased.

In addition, when the thread trimming link mechanism is used, the torque (physical quantity causing rotation of the object by acting on the object is also referred to as torsional moment) is not linear, the range of use is limited, There is a problem that the length of the piston and the rod becomes long to perform.

Published patent application No. 10-2011-0060619

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to reduce the weight and volume of an actuator by replacing a rod interlocked with an operation of a piston by a cable, And to provide a hydraulic actuator capable of smoothly changing the direction of the force.

According to an aspect of the present invention, there is provided a hydraulic actuator comprising: a reciprocating piston formed in association with movement of a fluid filled therein; A cylinder chamber provided so as to be positioned to the right; A cable connected to each of the cylinders through the piston to move in conjunction with the operation of the piston and to easily change the direction of the force; A pulley formed on one side of the cylinder chamber and having one or more cable receiving grooves formed on an outer circumferential surface formed in a disk shape so as to convert a transmission direction of a force or generate a large force with a small force; .

The cable is formed in at least one shape so as to be usable for a large force when engaged with a piston installed in a cylinder chamber.

The cable has a tension adjusting device formed at one end to smoothly adjust the tension so that slip does not occur when the cable moves (rotates) after the coupling with the pulley.

The pulleys are formed to have a large or small diameter in order to accelerate or decelerate the driving speed of the actuator.

The distance between the cylinder and the pulley is adjusted to be distant from or close to the length of the cable.

As described above, according to the present invention, the volume of the hydraulic actuator is reduced and the weight of the hydraulic actuator is reduced, thereby achieving miniaturization of the robot and the like and reducing the cost.

Further, since the torque of the pulley, which is a rotational motion part, is constant, the present invention can always provide a uniform power, so that the operation can be performed more precisely.

In addition, the present invention has the effect of making robots of various structures by designing the mechanism easily because the movement of the cable serving as a load is free and the direction of force is easy to change.

In addition, the present invention has the effect that the hydraulic actuator can generate a larger force than the same size.

1 is a schematic view illustrating a disassembly state of a hydraulic actuator according to a preferred embodiment of the present invention.
FIG. 2 is a perspective view showing the coupled state of FIG. 1. FIG.
3 is a sectional view of the main part of Fig.
FIG. 4 is a view illustrating a state in which the gripper is opened (opened) when the cable and the pulley move counterclockwise due to tension and compression of each piston and rotate when the hydraulic actuator according to the preferred embodiment of the present invention is used .
FIG. 5 is a view showing a state in which a hydraulic actuator according to a preferred embodiment of the present invention is in a state in which a cable and a pulley are moved in a clockwise direction by tension and compression of each piston, and a gripper portion is folded (closed) when rotated.
6 is a view showing a state in which a plurality of cable receiving grooves of a cable and a pulley are formed as another embodiment of the hydraulic actuator according to the present invention.

Hereinafter, preferred embodiments of the hydraulic actuator according to the present invention will be described in more detail with reference to the accompanying drawings.

Hereinafter, elements having the same function in all the following drawings will be denoted by the same reference numerals, and repetitive description will be omitted. Further, the following terms are defined in consideration of functions in the present invention, Should be interpreted as.

1 to 5, the present invention is roughly divided into a cylinder chamber 110, a cable 120, and a pulley 130.

The cylinder chamber 110 reciprocally moves in conjunction with the movement of the fluid 113, which is widely used as a medium for transferring power from oil filled in the cylinder chamber 110 The piston 111 is formed.

It is preferable that the cylinder chambers 110 are installed such that the pair of the chambers 110 are positioned up and down in the same direction, or are positioned to the left and the right.

As described above, since the pair of cylinder chambers 110 are arranged upward, downward, left, and right in the same direction, unlike the conventional actuator in which the pair of the actuators are disposed so as to face each other, So that a compact mechanism can be formed.

Further, the present invention is characterized in that a pair of cylinder chambers 110 are positioned in the same direction upward, downward, leftward and rightward, and the fluid 113 filled in one of the cylinder chambers 110 is moved, The fluid 113 in the other cylinder chamber 110 is interlocked with the other cylinder chamber 110 to operate the piston 111 to generate the compressive force.

As the hydraulic actuators 100 alternate with each other in this manner, the pulley 130, which couples and supports the cable 120 connected to each piston 111 and the cable 120, So that it can transmit forces or produce movements in both directions.

A seal for preventing the leakage of the fluid 113, which may be generated when the cable 120 is moved, is formed at one side of the cylinder chamber 110 and connected to the piston 111, (112) is formed.

The chamber 112 may be formed in the same or similar manner as the chamber for preventing leakage of the fluid during operation of the conventional piston rod, and thus a detailed description thereof will be omitted.

The cable 120 is formed by twisting a piano steel wire having a small diameter into a plurality of strands so that the cable 120 can be flexibly moved and flexed, such as bending or changing directions, so that durability and strength can be improved. And the intermediate portion is coupled through the cable receiving groove 131 of the pulley 130 to be interlocked with the operation of the piston 111.

Here, the cable 120 is moved forward or backward on one side with respect to the pulley 130 in conjunction with the operation of the piston 111, and the tether side is rotated clockwise or counterclockwise.

Since the cable 120 having such a configuration can significantly reduce the weight and volume as compared with the rod-shaped piston rod formed in the conventional actuator, the weight of the actuator can be reduced.

In addition to the piano steel wire, the cable 120 according to the present invention may be made of a variety of materials such as wire, other metal wire, or synthetic wire, as long as it is flexible and can improve durability and strength.

In addition, since the cable 120 is formed in a flexible form such as bending or turning, it is easy to design a mechanism including a universal joint of a robot or other device to which the actuator is mounted.

The cable 120 is preferably coated with a material such as urethane or Teflon to prevent leakage of the fluid 113 filled in the cylinder chamber 110 during a movement operation.

Accordingly, it is possible to more reliably prevent the leakage of the fluid 113 together with the seal 112 formed in the cylinder chamber 110.

A tension adjusting device 121 is formed at one end of the cable 120 so that tension adjustment can be smoothly performed so that slip does not occur when the cable 120 moves (rotates) after coupling with the pulley 130. [ .

Accordingly, the tension of the cable 120 is combined with the pulley 130 to prevent the slip of the pulley 130 when the pulley 130 is shifted to the opposite side. Therefore, the torque of the pulley 130, which acts on the object, The torsional moment is also referred to as a torsional moment), so that uniform power is provided to more accurately operate the joint mechanism portion of the robot or the gripper portion 140 of the medical robot.

Various constructions capable of accommodating the cable 120 and adjusting the tension can be used for the structure of the tension adjusting device 121, so a detailed description thereof will be omitted.

The pulley 130 is formed on one side of the cylinder chamber 110 and has a circular plate-like outer surface for transforming the direction of transmission of the force or generating a large force with a small force. A cable receiving groove 131 for receiving and supporting is formed.

The pulley 130 is rotated in both directions in accordance with the movement of the cable 120 interlocked with the movement of the piston 111. The pulley 130 is connected to the gripper portion of the robot, The gripper part 140 and the like can be smoothly performed.

More specifically, for example, when a pushing force is applied to the piston 111 by the expansion force of the fluid 113 filled in one of the cylinder chambers 110 of the pair of cylinder chambers 110 The piston 111 is moved to the left.

At this time, the fluid 113 filled in the other cylinder chamber 110 opposed to the cylinder chamber 110 in which the expansion force of the fluid 113 acts acts to generate a compressive force to pull the piston 111, 111) moves to the right.

The cable 120 is rotated through the cable receiving groove 131 of the pulley 130 to rotate the pulley 130 counterclockwise.

Therefore, the joint mechanism portion of the robot or the gripper portion 140 of the medical robot connected to the pulley 130 performs a spreading operation.

Conversely, when a pushing force is applied to the piston 111 by the expansion force of the fluid 113 filled in one of the cylinder chambers 110 among the pair of the cylinder chambers 110, the piston 111 moves to the left .

At this time, the fluid 113 filled in the other cylinder chamber 110 opposed to the cylinder chamber 110 in which the expansion force of the fluid 113 acts acts to generate a compressive force to pull the piston 111, 111) moves to the right.

The cable 120 is moved through the cable receiving groove 131 of the pulley 130 to rotate the pulley 130 in the clockwise direction.

Therefore, the joint mechanism portion of the robot connected to the pulley 130 or the gripper portion 140 of the medical robot performs the folding motion.

In addition, the pulley 130 may have a larger or smaller diameter so as to reduce or accelerate the rotation speed.

For example, assuming that the basic diameter of the pulley 130 is 30 mm, the diameter of the pulley 130, which requires fast operation of the joint mechanism portion of the robot or the gripper portion 140 of the medical robot, is smaller than 30 mm, The diameter of the pulley 130 requiring a slow operation is set to be larger than 30 mm so that the speed can be increased or decreased.

The hydraulic actuator 100 having such a structure can adjust the distance between the cylinder chamber 110 and the pulley 130 only by the length of the cable 120 so that a portion where the actual movement occurs, Can be achieved much more easily.

For example, when the gap between the cylinder chamber 110 and the pulley 130 is formed close to each other, the cable 120 is connected to the cable chamber 131 of the pulley 130 via the cable 120, 110 and the pulley 130 are spaced apart from each other, the cable 120 is connected to the cable receiving groove 131 of the pulley 130 by using the long cable 120 to cause actual movement with the hydraulic actuator 100 Can be easily adjusted.

This makes it much easier to design the mechanism of the part driven by the actuator, such as the joint mechanism part or the gripper part 140 of the robot.

The operation of the hydraulic actuator of the present invention having the above-described construction mounted on the medical robot will now be described.

4, when one of the pair of cylinder chambers 110 is opened, one of the pair of cylinder chambers 110 is opened, and when the gripper unit 140 is opened, The fluid 113 filled in the cylinder chamber 110 of the piston 111 is expanded and moved by the expansion force to push the piston 111 to the left.

At this time, the fluid 113 filled in the other cylinder chamber 110 opposed to the cylinder chamber 110 formed with the piston 111 moving to the left by the expansion force of the fluid 113 generates a compressive force do.

Accordingly, the piston 111 formed in the cylinder chamber 110 where the compression force is generated is moved to the right by the compressive force of the fluid.

The cable 120 is rotated through the cable receiving groove 131 of the pulley 130 to rotate the pulley 130 counterclockwise in conjunction with the operation of the piston 111. [

Accordingly, the gripper portion 140 of the medical robot connected to the pulley 130 performs an unfolding operation.

Conversely, when the gripper portion 140 of the medical robot is to be folded, as shown in FIG. 5, the fluid 113 (FIG. 5) filled in one of the cylinder chambers 110 among the pair of cylinder chambers 110 And pushes the piston 111 by an inflating force to move it to the left side.

At this time, the fluid 113 filled in the other cylinder chamber 110 opposed to the cylinder chamber 110 formed with the piston 111 moving to the left by the expansion force of the fluid 113 generates a compressive force do.

Accordingly, the piston 111 formed in the cylinder chamber 110 where the compression force is generated is moved to the right by the compressive force of the fluid.

The cable 120 is moved through the cable receiving groove 131 of the pulley 130 to rotate the pulley 130 in the clockwise direction in conjunction with the operation of the piston 111. [

Therefore, the gripper portion 140 of the medical robot connected to the pulley 130 performs a folding motion.

Therefore, by performing such a precise operation, a surgical tool or the like can be attached to the gripper portion 140 of the medical robot, so that the surgical operation can be performed more precisely and smoothly.

6 is a block diagram showing another embodiment of the present invention in which a plurality of cables 120 are installed on the piston 111 and a plurality of cables 120 are connected to the pulleys 130 A plurality of cable receiving grooves 131 may be formed on the outer circumferential surface of the pulley 130 so that the piston 111 may expand the area of pushing or pulling the fluid 113, It is able to generate about 2 times as much force with only about 50% power through easy rotation.

In other words, the cable 120 may be configured to exert a basic force by coupling one cable 120 to the center of the piston 111. However, the cable 120 may include two or more So that it is possible to exert a great force and at the same time to improve the durability.

In addition, the pulleys 130 may have at least one cable receiving groove 131 formed to accommodate the at least one cable 120.

Accordingly, the hydraulic actuator 100 according to the present invention has an advantage that it can exert a large force as compared with the conventional hydraulic actuator of the same size.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. And will be apparent to those skilled in the art to which the invention pertains.

100: Hydraulic actuator 110: Cylinder chamber
111: Piston 112: Seal
113: fluid 120: cable
121: tension adjusting device 130: pulley
131: Cable receiving groove 140: Gripper part

Claims (5)

As a hydraulic actuator
A cylinder chamber in which a pair of reciprocating pistons are interlocked with movement of a fluid filled in the cylinder, and the pair of cylinders are installed so as to be positioned up and down in the same direction;
A cable connected to each of the cylinders through the piston to move in conjunction with the operation of the piston and to easily change the direction of the force;
A pulley formed on one side of the cylinder chamber and having one or more cable receiving grooves formed on an outer circumferential surface formed in a disk shape so as to convert a transmission direction of a force or generate a large force with a small force; And a hydraulic actuator. The method according to claim 1,
Wherein the cable is formed in at least one of a shape capable of being used for a large force when engaged with a piston installed in a cylinder chamber. The method according to claim 1,
Wherein the tension adjusting device is formed at one end of the cable so as to smoothly adjust the tension so that slip does not occur when the cable is moved (rotated) after coupling with the pulley. The method according to claim 1,
Wherein the pulley is formed with a large diameter or a small diameter so as to accelerate or decelerate the driving speed of the actuator. The method according to claim 1,
And the distance between the cylinder and the pulley is adjusted to be distant from or close to the length of the cable.
KR1020140117401A 2014-09-04 2014-09-04 a hydraulic actuator KR20160029163A (en)

Priority Applications (1)

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KR1020140117401A KR20160029163A (en) 2014-09-04 2014-09-04 a hydraulic actuator

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KR1020140117401A KR20160029163A (en) 2014-09-04 2014-09-04 a hydraulic actuator

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101857137B1 (en) * 2017-12-04 2018-05-11 엘아이지넥스원 주식회사 Electro-hydraulic drive apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110060619A (en) 2009-11-30 2011-06-08 (주)엠에프테크 Actuator

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20110060619A (en) 2009-11-30 2011-06-08 (주)엠에프테크 Actuator

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101857137B1 (en) * 2017-12-04 2018-05-11 엘아이지넥스원 주식회사 Electro-hydraulic drive apparatus

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